xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision 1a28a37578c5e5d22b5a765d033548dbe0d3d134)
1  /*
2   * Copyright (c) 2000, Boris Popov
3   * All rights reserved.
4   *
5   * Redistribution and use in source and binary forms, with or without
6   * modification, are permitted provided that the following conditions
7   * are met:
8   * 1. Redistributions of source code must retain the above copyright
9   *    notice, this list of conditions and the following disclaimer.
10   * 2. Redistributions in binary form must reproduce the above copyright
11   *    notice, this list of conditions and the following disclaimer in the
12   *    documentation and/or other materials provided with the distribution.
13   * 3. All advertising materials mentioning features or use of this software
14   *    must display the following acknowledgement:
15   *    This product includes software developed by Boris Popov.
16   * 4. Neither the name of the author nor the names of any co-contributors
17   *    may be used to endorse or promote products derived from this software
18   *    without specific prior written permission.
19   *
20   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30   * SUCH DAMAGE.
31   *
32   * $FreeBSD$
33   */
34  
35  #include <sys/types.h>
36  #include <sys/param.h>
37  #include <sys/exec.h>
38  #include <sys/queue.h>
39  #include <sys/kernel.h>
40  #include <sys/reboot.h>
41  #include <sys/linker.h>
42  #include <sys/stat.h>
43  #include <sys/module.h>
44  #define FREEBSD_ELF
45  #include <link.h>
46  #include <err.h>
47  #include <fts.h>
48  #include <string.h>
49  #include <machine/elf.h>
50  #include <stdio.h>
51  #include <stdlib.h>
52  #include <unistd.h>
53  #include <errno.h>
54  
55  #include "ef.h"
56  
57  #define	MAXRECSIZE	1024
58  #define check(val)	if ((error = (val)) != 0) break
59  
60  static int dflag;	/* do not create a hint file, only write on stdout */
61  static int verbose;
62  
63  static FILE *fxref;	/* current hints file */
64  
65  static const char *xref_file = "linker.hints";
66  
67  /*
68   * A record is stored in the static buffer recbuf before going to disk.
69   */
70  static char recbuf[MAXRECSIZE];
71  static int recpos;	/* current write position */
72  static int reccnt;	/* total record written to this file so far */
73  
74  static void
75  intalign(void)
76  {
77  	recpos = (recpos + sizeof(int) - 1) & ~(sizeof(int) - 1);
78  }
79  
80  static void
81  record_start(void)
82  {
83  	recpos = 0;
84  	memset(recbuf, 0, MAXRECSIZE);
85  }
86  
87  static int
88  record_end(void)
89  {
90  	if (recpos == 0)
91  		return 0;
92  	reccnt++;
93  	intalign();
94  	fwrite(&recpos, sizeof(recpos), 1, fxref);
95  	return fwrite(recbuf, recpos, 1, fxref) != 1 ? errno : 0;
96  }
97  
98  static int
99  record_buf(const void *buf, int size)
100  {
101  	if (MAXRECSIZE - recpos < size)
102  		errx(1, "record buffer overflow");
103  	memcpy(recbuf + recpos, buf, size);
104  	recpos += size;
105  	return 0;
106  }
107  
108  /*
109   * An int is stored in host order and aligned
110   */
111  static int
112  record_int(int val)
113  {
114  	intalign();
115  	return record_buf(&val, sizeof(val));
116  }
117  
118  /*
119   * A string is stored as 1-byte length plus data, no padding
120   */
121  static int
122  record_string(const char *str)
123  {
124  	int len, error;
125  	u_char val;
126  
127  	if (dflag)
128  		return 0;
129  	val = len = strlen(str);
130  	if (len > 255)
131  		errx(1, "string %s too long", str);
132  	error = record_buf(&val, sizeof(val));
133  	if (error)
134  		return error;
135  	return record_buf(str, len);
136  }
137  
138  static int
139  parse_entry(struct mod_metadata *md, const char *cval,
140      struct elf_file *ef, const char *kldname)
141  {
142  	struct mod_depend mdp;
143  	struct mod_version mdv;
144  	Elf_Off data = (Elf_Off)md->md_data;
145  	int error = 0;
146  
147  	record_start();
148  	switch (md->md_type) {
149  	case MDT_DEPEND:
150  		if (!dflag)
151  			break;
152  		check(EF_SEG_READ(ef, data, sizeof(mdp), &mdp));
153  		printf("  depends on %s.%d (%d,%d)\n", cval,
154  		    mdp.md_ver_preferred, mdp.md_ver_minimum, mdp.md_ver_maximum);
155  		break;
156  	case MDT_VERSION:
157  		check(EF_SEG_READ(ef, data, sizeof(mdv), &mdv));
158  		if (dflag) {
159  			printf("  interface %s.%d\n", cval, mdv.mv_version);
160  		} else {
161  			record_int(MDT_VERSION);
162  			record_string(cval);
163  			record_int(mdv.mv_version);
164  			record_string(kldname);
165  		}
166  		break;
167  	case MDT_MODULE:
168  		if (dflag) {
169  			printf("  module %s\n", cval);
170  		} else {
171  			record_int(MDT_MODULE);
172  			record_string(cval);
173  			record_string(kldname);
174  		}
175  		break;
176  	default:
177  		warnx("unknown metadata record %d in file %s", md->md_type, kldname);
178  	}
179  	if (!error)
180  		record_end();
181  	return error;
182  }
183  
184  static int
185  read_kld(char *filename, char *kldname)
186  {
187  	struct mod_metadata md;
188  	struct elf_file ef;
189  	void **p, **orgp;
190  	int error, eftype, nmlen;
191  	long start, finish, entries;
192  	char kldmodname[MAXMODNAME + 1], cval[MAXMODNAME + 1], *cp;
193  
194  	if (verbose || dflag)
195  		printf("%s\n", filename);
196  	error = ef_open(filename, &ef, verbose);
197  	if (error) {
198  		error = ef_obj_open(filename, &ef, verbose);
199  		if (error) {
200  			if (verbose)
201  				warnc(error, "elf_open(%s)", filename);
202  			return error;
203  		}
204  	}
205  	eftype = EF_GET_TYPE(&ef);
206  	if (eftype != EFT_KLD && eftype != EFT_KERNEL)  {
207  		EF_CLOSE(&ef);
208  		return 0;
209  	}
210  	if (!dflag) {
211  		cp = strrchr(kldname, '.');
212  		nmlen = (cp != NULL) ? cp - kldname : (int)strlen(kldname);
213  		if (nmlen > MAXMODNAME)
214  			nmlen = MAXMODNAME;
215  		strlcpy(kldmodname, kldname, nmlen);
216  /*		fprintf(fxref, "%s:%s:%d\n", kldmodname, kldname, 0);*/
217  	}
218  	do {
219  		check(EF_LOOKUP_SET(&ef, MDT_SETNAME, &start, &finish,
220  		    &entries));
221  		check(EF_SEG_READ_ENTRY_REL(&ef, start, sizeof(*p) * entries,
222  		    (void *)&p));
223  		orgp = p;
224  		while(entries--) {
225  			check(EF_SEG_READ_REL(&ef, (Elf_Off)*p, sizeof(md),
226  			    &md));
227  			p++;
228  			check(EF_SEG_READ(&ef, (Elf_Off)md.md_cval,
229  			    sizeof(cval), cval));
230  			cval[MAXMODNAME] = '\0';
231  			parse_entry(&md, cval, &ef, kldname);
232  		}
233  		if (error)
234  			warnc(error, "error while reading %s", filename);
235  		free(orgp);
236  	} while(0);
237  	EF_CLOSE(&ef);
238  	return error;
239  }
240  
241  /*
242   * Create a temp file in directory root, make sure we don't
243   * overflow the buffer for the destination name
244   */
245  static FILE *
246  maketempfile(char *dest, const char *root)
247  {
248  	char *p;
249  	int n, fd;
250  
251  	p = strrchr(root, '/');
252  	n = p != NULL ? p - root + 1 : 0;
253  	if (snprintf(dest, MAXPATHLEN, "%.*slhint.XXXXXX", n, root) >=
254  	    MAXPATHLEN) {
255  		errno = ENAMETOOLONG;
256  		return NULL;
257  	}
258  
259  	fd = mkstemp(dest);
260  	if (fd < 0)
261  		return NULL;
262  	fchmod(fd, 0644);	/* nothing secret in the file */
263  	return fdopen(fd, "w+");
264  }
265  
266  static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
267  
268  static void
269  usage(void)
270  {
271  
272  	fprintf(stderr, "%s\n",
273  	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
274  	);
275  	exit(1);
276  }
277  
278  int
279  main(int argc, char *argv[])
280  {
281  	FTS *ftsp;
282  	FTSENT *p;
283  	int opt, fts_options, ival;
284  	struct stat sb;
285  
286  	fts_options = FTS_PHYSICAL;
287  
288  	while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
289  		switch (opt) {
290  		case 'd':	/* no hint file, only print on stdout */
291  			dflag = 1;
292  			break;
293  		case 'f':	/* use this name instead of linker.hints */
294  			xref_file = optarg;
295  			break;
296  		case 'v':
297  			verbose++;
298  			break;
299  		case 'R':	/* recurse on directories */
300  			fts_options |= FTS_COMFOLLOW;
301  			break;
302  		default:
303  			usage();
304  			/* NOTREACHED */
305  		}
306  	}
307  	if (argc - optind < 1)
308  		usage();
309  	argc -= optind;
310  	argv += optind;
311  
312  	if (stat(argv[0], &sb) != 0)
313  		err(1, "%s", argv[0]);
314  	if ((sb.st_mode & S_IFDIR) == 0) {
315  		errno = ENOTDIR;
316  		err(1, "%s", argv[0]);
317  	}
318  
319  	ftsp = fts_open(argv, fts_options, 0);
320  	if (ftsp == NULL)
321  		exit(1);
322  
323  	for (;;) {
324  		p = fts_read(ftsp);
325  		if ((p == NULL || p->fts_info == FTS_D) && fxref) {
326  			/* close and rename the current hint file */
327  			fclose(fxref);
328  			fxref = NULL;
329  			if (reccnt) {
330  				rename(tempname, xrefname);
331  			} else {
332  				/* didn't find any entry, ignore this file */
333  				unlink(tempname);
334  				unlink(xrefname);
335  			}
336  		}
337  		if (p == NULL)
338  			break;
339  		if (p->fts_info == FTS_D && !dflag) {
340  			/* visiting a new directory, create a new hint file */
341  			snprintf(xrefname, sizeof(xrefname), "%s/%s",
342  			    ftsp->fts_path, xref_file);
343  			fxref = maketempfile(tempname, ftsp->fts_path);
344  			if (fxref == NULL)
345  				err(1, "can't create %s", tempname);
346  			ival = 1;
347  			fwrite(&ival, sizeof(ival), 1, fxref);
348  			reccnt = 0;
349  		}
350  		/* skip non-files or .symbols entries */
351  		if (p->fts_info != FTS_F)
352  			continue;
353  		if (p->fts_namelen >= 8 &&
354  		    strcmp(p->fts_name + p->fts_namelen - 8, ".symbols") == 0)
355  			continue;
356  		read_kld(p->fts_path, p->fts_name);
357  	}
358  	fts_close(ftsp);
359  	return 0;
360  }
361